Machined parts for various applications, such as turbine airfoils, compressor fans, blade roots, etc., may have edges shaped for achieving specified mechanical properties, including avoidance or reduction of stress concentrations. Features and/or geometric discontinuities that could give rise to edge sharpness, such as may be encountered in a chamfer, bevel, fillet and other part features will be referred to in the context of this description as an edge break.
Inspection of edge breaks, either for manufacturing quality control or for determination of part wear, has been time consuming and burdensome. In past practice, edge breaks have been measured using a wax or soft-metal impression of the edge. The impression is then measured using a stylus or a tracer-type of mechanical gage, or is sectioned on planes normal to the line of the edge, and viewed using an optical comparator. This practice is generally time consuming and inexact due to challenges in making an accurate replica of the edge break, and obtaining a correct cross sectional mapping.
Known devices for performing non-contact 3D surface profiling with structured light patterns in general have not been user-friendly for performing fast measurements in a manufacturing setting due to their lack of portability and difficulties associated with the handling of such devices. For example, the weight and size of such devices are generally not conducive to enable service personnel to quickly and accurately inspect multiple parts that may be located in multiple locations of a manufacturing plant floor.
Thus it is desirable to provide an edge break gage not subject to the foregoing shortcomings.